"The poor man and the oppressor have this in common: the Lord gives light to the eyes of both"
This is the Hebrew word rush which means to be in want, poor, destitute. This is a very poor person. One who lacks basic necessities.
This is the word tok which means oppression, oppressor, fraud, deceitful. The idea is that these two people on the surface look completely different, but they have a number of commonalities. Solomon does not want to let them forget these commonalities. There is a being behind all of their actions supplying power and ability to them. That would be God.
Many times you can take for granted what is supplied to you by God and believe that somehow you are inherently better or different than other people, but God is the hidden power source and the invisible maintainer of your life. Do not become so independent in your thinking that you believe you don't need God or that the other person is fundamentally different or less than you.
We have to be careful about this because it happens over class, education, race, ethnicity, religion, etc. All these become the basis for people to believe that they are better than other people, but God is the sustainer and maintainer of life behind the scenes.
Do not for any reason believe that you are better than another human being. You share a common history and future with humanity. Humans were made in the image of God; they have dignity. Humans are also tainted with selfishness.